Propriedades magneticas de um gas de eletrons semiclassico

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

We study the semiclassical magnetization and the susceptibility of non-interacting electrons gas confined by a smooth chaotic potential. The magnetization per particle, m, is directly related to the staircase function N(E), which counts the single-particle levels up to energy E. Using Gutzwiller s trace formula for N, we derive a semiclassical expression for m. Our results show that the magnetization has a non-zero average, which arises from corrections to the leading-order Weyl approximation to the mean staircase and which is independent of whether the classical motion is chaotic or not. Fluctuations about the average are due to classical periodic orbits and do represent a signature of chaos. The computation of the susceptibility, x, for a wide range of magnetic field values B reveals that the chaotic (B = O) to regular (B ® ¥) transition is dominated by bifurcations of short periodic orbits that become stable as B increases. Large contributions are observed near the bifurcations points, increasing the average susceptibility to values beyond those expected for regular systems.

ASSUNTO(S)

magnetização comportamento caotico nos sistemas

ACESSO AO ARTIGO

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